Lukas Hoffmann is a software engineer who works remotely for a company in Munich. In September 2025 his wife and their two children, aged seven and ten, settled in Marbella; he kept his flat in Munich and splits his time between the two cities. In 2026 he will spend about 160 days in Spain. His German adviser warns him that Germany still sees him as resident. His Spanish bank, on the other hand, asks him for a certificate of tax residence in Spain. Lukas wonders which administration he should turn to, and whether asking for one of the two certificates settles the argument.
It does not. And asking for a certificate before putting the evidence in order is the quickest way to end up holding two contradictory documents.
Each administration answers under its own law
The Spanish Agencia Tributaria (the tax agency) certifies what follows from its data in the light of article 9 of the IRPF Act (the Spanish personal income tax). The German administration will do the same under its own rules, on which we express no view: that is for Lukas's adviser there to confirm. Nothing prevents both from concluding that Lukas lives in their territory, because each applies different criteria.
In Spain, article 9.1 provides that you are resident if either of these circumstances applies:
- You stay more than 183 days of the calendar year in Spanish territory, with sporadic absences counted unless you prove your tax residence in another country.
- Spain is where the main core or base of your activities or economic interests lies, directly or indirectly.
And it adds a presumption, rebuttable by evidence to the contrary: residence is presumed when the spouse who is not legally separated and the dependent minor children habitually live in Spain. That is exactly Lukas's case.
Lukas's days, counted as Hacienda would count them
Suppose this split in 2026:
| Item | Days |
|---|---|
| Days physically in Spain | 160 |
| Short trips away from Marbella, returning home (holidays, conferences) | 45 |
| Days working in Munich | 160 |
- If only days of physical presence are counted, Lukas is below 183.
- But article 9.1.a) counts sporadic absences. If the 45 days of trips are treated as sporadic, the total becomes 160 + 45 = 205 days.
- With 205 days, he exceeds the presence threshold on that ground alone.
- The only way the rule provides for those absences not to be added is to prove tax residence in another country.
Here is the paradox: the German certificate, which Lukas saw as a problem, is precisely the document the Spanish law mentions for excluding sporadic absences from the count. And even then, the family presumption would still stand and would have to be rebutted with evidence.
How it is decided when both laws say "mine"
If there is a double taxation treaty between the two States, its article on residence contains tie-breaker rules. In treaties that follow the OECD Model, the order is usually as follows, and you only move to the next criterion if the previous one does not settle the matter:
- A permanent home available to you. If you have only one, that country wins. Lukas has two.
- Centre of vital interests. The State with which your personal and economic relations are closer.
- Habitual abode. Where you habitually spend more time.
- Nationality.
- Agreement between the competent authorities of both States.
The exact wording changes from one treaty to another, so the practical rule is to read the article of the specific treaty before reasoning about it. The guide on dual residence conflicts develops it in more detail.
What evidence to prepare before asking for anything
Each tie-breaker criterion is won or lost on documents. Gathering them before applying for a certificate lets you know which of the two positions can be sustained.
| Criterion | Documents that support it |
|---|---|
| Permanent home | Deeds or tenancy agreements for each home, and who uses them |
| Personal relations | Where the spouse and children live, school enrolment, municipal registration, family doctor |
| Economic relations | Where the employer is, where the work is done, where the accounts and investments are |
| Habitual abode | A calendar of days in each country, boarding passes, statements showing where payments were made |
| Nationality | Passport, only if everything above is tied |
For Lukas, the family in Marbella pushes the centre of vital interests towards Spain; the employer, the salary and the Munich flat pull towards Germany. There is no obvious answer, and anyone who promises him one is guessing. What can be done is to put the calendar together precisely, which is the first thing either administration will ask for.
If you are in a similar position and would like us to review the evidence before you apply for anything, you can tell us about it in the certificate form.
The Spanish treaty certificate says that you are resident in Spain within the meaning of the treaty with the other State. Asking for it while your residence is in dispute, without having analysed the tie-breaker criteria, can produce a document that later contradicts your own returns in the other country. It is not a neutral formality: what is certified can later be used in any tax check.
The family presumption can be rebutted, but with facts
The presumption in article 9 admits evidence to the contrary. That means Lukas can try to show that, although his family lives in Marbella, his residence is not in Spain. What he cannot do is rebut it with a statement of intent. Verifiable facts are needed: where he physically works each day, where his assets are, where he receives his salary, how much time he spends with his family and where. If the honest result of that exercise is that his life is split almost evenly, the likely conclusion is that Spain will treat him as resident and the solution will have to be sought in the treaty, not in domestic law.
So who do you ask?
It depends on what you need it for and where you turn out to be resident after applying the treaty:
- If the reasonable conclusion is that you live in Spain, the certificate is issued by the Spanish Agencia Tributaria, and the version that mentions the treaty with Germany is the one that makes sense for any use with German payers. The difference between the two forms is in ordinary and treaty certificates.
- If the conclusion is that you live in Germany, Lukas asks his own administration for the certificate, through his adviser there. In Spain he would use it, among other things, to prove that he is non-resident and pay tax only on income obtained here.
- If no conclusion is clear, the prudent course is not to request either one yet for any use that involves invoking the treaty, and to document the year first.
Lukas's bank, incidentally, probably does not need an official certificate but a self-certification of residence. We explain it in which certificate the bank wants.
When it is too late to prevent it
If both States have already issued a certificate, or if one of them has assessed tax on the footing that you are resident, the situation is different: the conflict has to be resolved through the routes the treaty offers. We deal with that in two countries give me a certificate: which one prevails.
The Salama Tax page describes the general procedure for the certificate. In a residence conflict there is no guaranteed outcome: what can be done is to build the best possible evidence before someone else asks for it.